A5028912961- Atmospheric Ozone and Climate
- Atmospheric chemistry and aerosols
- Atmospheric and Environmental Gas Dynamics
- Air Quality Monitoring and Forecasting
- Climate variability and models
- Atmospheric aerosols and clouds
- Ocean Acidification Effects and Responses
- Air Quality and Health Impacts
- Vehicle emissions and performance
- Meteorological Phenomena and Simulations
- Ionosphere and magnetosphere dynamics
- Spectroscopy and Laser Applications
- Water Quality Monitoring and Analysis
- Fire effects on ecosystems
- Marine and coastal ecosystems
- Geophysics and Gravity Measurements
- Gas Sensing Nanomaterials and Sensors
- Spaceflight effects on biology
- Tropical and Extratropical Cyclones Research
- Spacecraft and Cryogenic Technologies
- Maritime Transport Emissions and Efficiency
- Precipitation Measurement and Analysis
- Oceanographic and Atmospheric Processes
- Analytical Chemistry and Sensors
- Medical and Biological Ozone Research
NSF National Center for Atmospheric Research
2020-2023
University of Ontario Institute of Technology
2023
University of Utah
2023
University of Notre Dame
2023
SA Photonics (United States)
2023
Goddard Space Flight Center
2010-2021
Science Systems and Applications (United States)
2011-2021
University of Maryland, Baltimore County
2021
Support Systems Associates (United States)
2004
McGill University
1996
Since 1996, quality assurance experiments of electrochemical concentration cell (ECC) ozonesondes two different model types (SPC‐6A and ENSCI‐Z) have been conducted in the environmental simulation facility at Research Centre Juelich within framework Ozone Sonde Intercomparison Experiment (JOSIE). The shown that performance characteristics ECC‐sonde can be significantly different, even when operated under same conditions. Particularly above 20 km ENSCI‐Z sonde tends to measure 5–10% more...
A network of 10 southern hemisphere tropical and subtropical stations, designated the Southern Hemisphere Additional Ozonesondes (SHADOZ) project established from operational sites, provided over 1000 ozone profiles during period 1998–2000. Balloon‐borne electrochemical concentration cell (ECC) ozonesondes, combined with standard radiosondes for pressure, temperature, relative humidity measurements, collected in troposphere lower to midstratosphere at: Ascension Island; Nairobi, Kenya;...
Abstract. Past studies have suggested that ozone in the troposphere has increased globally throughout much of 20th century due to increases anthropogenic emissions and transport. We show, by combining satellite measurements with a chemical transport model, during last four decades tropospheric does indeed indicate are global nature, yet still highly regional. Satellite from Nimbus-7 Earth Probe Total Ozone Mapping Spectrometer (TOMS) merged Aura Monitoring Instrument/Microwave Limb Sounder...
Abstract Electrochemical concentration cell ozonesonde measurements are an important source of highly resolved vertical profiles ozone (O 3 ) with long‐term data records for deriving O trends, model development, satellite validation, and air quality studies. Ozonesonde stations employ a range operational processing procedures, metadata reporting, instrument changes that have resulted in inhomogeneities within individual station records. A major milestone is the first reprocessing seven...
Abstract Understanding lowermost stratosphere (LMS) ozone variability is an important topic in the trends and climate assessment communities because of feedbacks among changing temperature, dynamics, ozone. LMS evaluations are usually based on satellite observations. Free tropospheric (FT) assessments typically rely profiles from commercial aircraft. Ozonesonde measurements constitute independent data set encompassing both FT. We used Southern Hemisphere Additional Ozonesondes (SHADOZ)...
Abstract We review the current state of knowledge ozonesonde uncertainty and bias, with reference to recent developments in laboratory field experiments. In past 20 years precision has improved by a factor 2, primarily through adoption strict standard operating procedures. The budget for ozone partial pressure reading contributions from stoichiometry, cell background current, pump efficiency temperature, sensing solution type, volume. Corrections historical data known issues may reduce...
New methods for retrieving tropospheric ozone column depth and absorbing aerosol (smoke dust) from the Earth Probe–Total Ozone Mapping Spectrometer (EP/TOMS) are used to follow pollution determine interannual variability trends. During intense fires over Indonesia (August November 1997), plumes, decoupled smoke below, extended as far India. This overlay a regional increase triggered by atmospheric responses El Niño Indian Ocean Dipole. Tropospheric measurements Nimbus 7 TOMS instrument show...
The first view of stratospheric and tropospheric ozone variability in the Southern Hemisphere tropics is provided by a 3‐year record soundings from Additional Ozonesondes (SHADOZ) network ( http://croc.gsfc.nasa.gov/shadoz ). Observations covering 1998–2000 were made over Ascension Island, Nairobi (Kenya), Irene (South Africa), Réunion Watukosek (Java), Fiji, Tahiti, American Samoa, San Cristóbal (Galapagos), Natal (Brazil). Total, stratospheric, column amounts usually peak between August...
We compare Tropospheric Emission Spectrometer (TES) version 2 (V002) nadir ozone profiles with ozonesonde from the Intercontinental Chemical Transport Experiment Ozonesonde Network Study, World Ozone and Ultraviolet Data Center, Global Monitoring Division of Earth System Research Laboratory, Southern Hemisphere Additional archives. Approximately 1600 coincidences spanning 72.5°S–80.3°N October 2004 to 2006 are found. The TES averaging kernel constraint applied data account for measurement...
Abstract. A global climatology of tropospheric and stratospheric column ozone is derived by combining six years Aura Ozone Monitoring Instrument (OMI) Microwave Limb Sounder (MLS) measurements for the period October 2004 through December 2010. The OMI/MLS exhibits large temporal spatial variability which includes accumulation zones in tropical south Atlantic year-round subtropical Mediterranean/Asia region summer months. High levels Northern Hemisphere also persist mid-latitudes over eastern...
A balloon flight to compare 18 ozonesondes with an ozone photometer and column measurements from Dobson Brewer spectrophotometers was completed in April 2004. The core experiment consisted of 12 electrochemical concentration cell ozonesondes, 6 Science Pump Corporation (SP) ENSCI (ES), prepared cathode solution concentrations 0.5% KI (half buffer) 1.0% (full buffer). Auxiliary two sondes 2.0% (no buffer), reconditioned sondes, Japanese‐KC96 sondes. Precision each group similarly <2–3%....
On Monday, 19 July, and Tuesday, 20 July 2004, the air over Houston, Texas, appeared abnormally hazy. Transport model results data from Atmospheric Infrared Sounder (AIRS), Moderate Resolution Imaging Spectrometer (MODIS), Measurement of Ozone by Airbus In‐service airCraft (MOZAIC) experiment, Total Mapping (TOMS) indicate that an mass originating on 12 2004 forest fires in eastern Alaska western Canada arrived Houston about 1 week later. Ozonesonde show elevated ozone at surface (>125...
The Southern Hemisphere Additional Ozonesondes (SHADOZ) project has collected more than 3000 ozone profiles from 14 tropical and subtropical sites using balloon‐borne electrochemical concentration cell (ECC) ozonesondes flown with standard radiosondes. Published analysis of ozonesonde precision SHADOZ measured in 1998–2000 revealed that variations technique might cause small station‐to‐station biases the total measurement. We present further evaluation imprecisions accuracy based on...
For the August‐September 2008 Olympic and Paralympic Games held in Beijing, China, strict controls on pollutant emissions motor vehicle traffic were imposed Beijing neighboring provinces to South improve air quality around city. Satellite measurements over between July September showed 43% reductions of tropospheric column nitrogen dioxide, compared past three years. When south are included our analyses, satellite show boundary layer sulfur dioxide 13% carbon monoxide 12% at 700 hPa. Thus,...
Abstract The Southern Hemisphere ADditional OZonesonde (SHADOZ) network was assembled to validate a new generation of ozone‐monitoring satellites and better characterize the vertical structure tropical ozone in troposphere stratosphere. Beginning with nine stations 1998, more than 7,000 P ‐ T U profiles are available from 14 SHADOZ sites that have operated continuously for at least decade. We analyze recently reprocessed data set is based on adjustments inconsistencies caused by varying...
Abstract. Wildfires raged throughout western Russia and parts of Eastern Europe during a persistent heat wave in the summer 2010. Anomalously high surface temperatures (35–41 °C) low relative humidity (9–25 %) from mid-June to mid-August 2010 shown by analysis radiosonde data multiple sites were ideal conditions for wildfires thrive. Measurements outgoing longwave radiation (OLR) Atmospheric Infrared Sounder (AIRS) over Russian indicate subsidence wave. Daily three-day back-trajectories...
Abstract Reprocessed ozonesonde data from eight SHADOZ (Southern Hemisphere ADditional OZonesondes) sites have been used to derive the first analysis of uncertainty estimates for both profile and total column ozone (TCO). The is a composite uncertainties individual terms in partial pressure ( P O3 ) equation, those being sensor current, background internal pump temperature, efficiency factors, conversion efficiency, flow rate. Overall, (Δ are within 15% peak around tropopause (15 ± 3 km)...
Abstract We investigate the observed trends and interannual variability in surface ozone over United States using Global Modeling Initiative chemical transport model. discuss roles of meteorology, emissions, from stratosphere driving different regions seasons. demonstrate that a hindcast simulation for 1991–2010 can reproduce much summertime ozone, with correlation coefficients seasonally regionally averaged median ranging 0.46 to 0.89. Reproducing winter spring western may require...
Abstract. NOAA's program of long-term monitoring the vertical distribution ozone with electrochemical concentration cell (ECC) ozonesondes has undergone a number changes over 50-year record. In order to produce homogenous data set, these must be documented and, where necessary, appropriate corrections applied. This is first comprehensive and consistent reprocessing ozonesonde records that corrects for using rawest form (cell current pump temperature) in native resolution as well...
Abstract. Ozone is a key constituent of the troposphere, where it drives photochemical processes, impacts air quality, and acts as climate forcer. Large-scale in situ observations ozone commensurate with grid resolution current Earth system models are necessary to validate model outputs satellite retrievals. In this paper, we examine measurements from Atmospheric Tomography (ATom; four deployments 2016–2018) HIAPER Pole-to-Pole Observations (HIPPO; five 2009–2011) experiments, two...
Abstract An international effort to improve ozonesonde data quality and reevaluate historical records has made significant improvements in the accuracy of global network data. However, between 2014 2016, total column ozone (TCO; O 3 ) at 14 37 regularly reporting stations exhibited a sudden dropoff relative satellite measurements. The TCO drop is 3–7% compared ground‐based TCO, 5–10% or more stratospheric profiles, compromising use recent for trends, although they remain reliable other uses....
Abstract The ozonesonde is a small balloon-borne instrument that attached to standard radiosonde measure profiles of ozone from the surface 35 km with ∼100-m vertical resolution. Ozonesonde data constitute mainstay satellite calibration and are used for climatologies analysis trends, especially in lower stratosphere where satellites most uncertain. electrochemical concentration cell (ECC) has been deployed at ∼100 stations worldwide since 1960s, changes over time manufacture procedures,...
During the Aerosols99 trans‐Atlantic cruise from Norfolk, VA, to Cape Town, South Africa, daily ozonesondes were launched R/V Ronald H Brown between 17 January and 6 February 1999. A composite of tropospheric ozone profiles along latitudinal transect shows 4 zones, nearly identical distribution during a January‐February 1993 [Weller et al., 1996]. Sondes Ascension Island (8S, 14.5W), as well Earth‐Probe (EP)/TOMS satellite instrument, show elevated (>35 Dobson Units) throughout south...
The climatological ozone profile in the tropics is shaped like an “S,” with a minimum at surface, maximum 330 K (∼6.5 km), another 345 (∼11.2 and subsequent increase toward tropopause. These features can be reproduced by very simple model whose only free parameter mean mixing ratio of air detraining from deep convective clouds. To first order, arises balance between vertical advection, convection, chemistry. coincident lapse rate minimum. Both minima are associated large outflow followed...
The most extensive set of free tropospheric ozone measurements ever compiled across midlatitude North America was measured with daily ozonesondes, commercial aircraft and a lidar at 14 sites during July‐August 2004. model estimated stratospheric subtracted from all profiles, leaving residual ozone. On average the upper troposphere above eastern contained 15 ppbv more than polluted layer between surface 2 km sea level. Lowest values in were found two upwind California. 16 three sites,...